[ShriD5]

Ports Zeron commits after 8b7afb30, through d643a2ca.

Ported

• b1d4927f: direct links let WebRTC packets fragment, so P2P links over Tailscale (MTU 1280) carry data. Conflict in preview/peer.rs: Godspeed has no setting_engine() (it comes from the deferred dfbb6876), so only .with_runtime(...) was added.
• b28c9953: fx as a native ACP provider (fx acp). Adapted to Godspeed:
  • dropped upstream's access_modes/supports_plan descriptor/spec fields (from the deferred 1295d577)
  • the forced mode=ask and model writes use request_draining
  • Godspeed's own approval logic answers permissions under every access mode
  • added Fx to instance.rs, provider_instance.rs (no config-dir var) and the install table/tests
  • providers.rs doesn't exist in Godspeed, so that hunk was dropped
  • fx tests use set_access_mode plus a local answering_controls helper
  • README section renamed to Godspeed
  • dropped docs/screenshots

Deferred (owner's call, recorded in UPSTREAM.md)

• 6aa4d5af: background processes tray. Godspeed already publishes a background_tasks: u32 count on the session row under the same backgroundTasks wire key that upstream turns into Vec<BackgroundTask>. Delegation wake-ups and the busy indicator use that count, and older peers would fail to read the new rows. Porting it needs a wire decision first, and 26 files conflict.

Skipped

• a0468502, 1bb6259c, d643a2ca: edge user directory, hosted edge only
• 369d4281: version bump

Tests (CARGO_TARGET_DIR on Lexar)

• cargo build -p godspeed, cargo check --workspace --tests: ok
• zeron-engine lib: 759 passed, 6 failed under load (fs_watch ×3, explicit_install_rpc, workspace_files search ×2); all pass rerun alone (known load flakes)
• engine e2e / always_on_agents / telegram_bot: ok, except file_changes_fire_one_debounced_run (known flake), which passes alone
• zeron-harness lib: 429 passed, 1 failed (version_probe_bounds_hangs_and_rejects_nonzero, known), which passes alone
• harness acp test (incl. 3 new fx tests): 80 passed
• zeron-preview + zeron-proto: ok (incl. new direct_link_sockets_may_fragment)
• zeron-ui lib (--test-threads=1): 2149 passed